Updates R shunt test

ohmpi/test/tests.py

@@ -453,7 +453,7 @@ class OhmPiTests():
             self._hw.switch_mux(quad, roles, state='on', bypass_ab_check=True)
             self._hw.tx.pwr._voltage_max = 2.
             self._hw.tx.pwr._current_max_tolerance = 0.
-            self._hw.tx.pwr.current_max = 0.050 # mA
+            self._hw.tx.pwr.current_max = 0.045 # mA
             # self._hw._vab_pulse(duration=injection_duration, vab=tx_volt)
             time.sleep(.5)
             injection = Thread(target=self._hw._inject, kwargs={'injection_duration': injection_duration, 'polarity': 1})